Patent Document 1 discloses a power supply box device to be mounted to and removed from (attached to and detached from) a wiring duct from below.
Attachment and detachment of a power supply box device of this type is generally performed by rotating forward or backward an operation lever that protrudes in a radial direction from a plug body.
For example, when the power supply box is to be mounted, an operator holds the power supply box device with one hand, and inserts a plug electrode or a fixing member into a duct groove of a wiring duct, and rotates the operation lever forward with the other hand. By this operation, the power supply box is electrically connected and secured to the wiring duct. On the other hand, when the power supply box is to be removed, the operator holds the power supply box device with one hand, and rotates the operation lever backward with the other hand. By this operation, the electrical connection and the securing to the duct is released and then the power supply box device is removed from the wiring duct.
The attachment and detachment of the power supply box device described above is performed to the ceiling, and thus the operator needs to handle the operation lever in an unnatural posture, for example, standing on a stepladder with operator's hands raised upward.
For this reason, the operation lever has a size easy to handle and is disposed in a position easy to operate, for example, in a position protruding in a radial direction from the plug body.